function reloadCode() {
    document.getElementById("imagecode").src="<%= request.getContextPath()%>/imageGenerate?time" + new Date().getTime();
}
function checkUserName(){
    var username=document.getElementById("userName").value;

    if(username==''){
        alert("用户名不能为空");return false;
    } else{
        return true;
    }
}
function checkPassWord(){
    var password=document.getElementById("userPwd").value;
    if(password==''){
        alert("密码不能为空");return false;
    }else{
        return true;
    }
}
